1. Field of the Invention
The invention relates generally to food processing and especially to food flavor chemistry.
In particular, this invention concerns the direct conversion of a food into an ethereal salt.
2. Background Art
Ethereal salts, more commonly known as esters, are formed during the manufacture of food products by fermentation. Esters impart aromatic and flavor characteristics to foods and are critical to consumer taste acceptance.
The fermentation procedure involves the chemical conversion of organic food substances by the action of ferments, such as enzymes produced by molds, bacteria and yeast. Typically, food is inoculated with selected enzymes and, over a period of time, the enzymes breakdown the food to form carbon dioxide and other products, such as alcohol. For example, in alcoholic fermentation, the action of zymase, secreted by yeast, converts simple sugars, such as glucose and fructose, into ethyl alcohol and carbon dioxide. The reaction of an organic acid with alcohol leads to the formation of an ester.
In the process of esterification, the hydroxyl group of the acid combines with the hydrogen atom of the hydroxyl radical in the alcohol to form water, the other product being the ester. These reactions are nonionic and therefore proceed very slowly. An equilibrium state is established only when sufficient time has been allowed to elapse.
A disadvantage of this esterification procedure is that a delayed-action or "aging" of the food product is required in order to reach equilibrium. For example, some food products must be "aged" for several years. Consequently, the production cycle-time and the related cost factors are adversely affected by the time lapse.
An attempt to accelerate the rate of esterification and aging of distilled liquor is disclosed in U.S. Pat. No. 5,173,318; however, the procedure described does not eliminate the intermediate fermented product.
Another shortcoming with the formation of esters by a fermentation procedure is that the aging must be maintained under controlled conditions of temperature and acidity that require continuous monitoring. Additionally, when the food product is fully aged, it must then be pasteurized to eliminate microbes present in the enzymes. A problem with this thermal treatment is that it indiscriminately destroys both desirable and undesirable microbes. Certain microbes are beneficial in that they provide an enzymatic action for tenderizing meat and poultry and preferably should remain in certain food products, for example, in steak sauces. Other drawbacks inherent in food pasteurization is the deterioration of flavor and the detrimental alteration of nutritional value. Another limitation of the fermentation procedure is that the food product must be clarified to remove impurities that become entrained during fermentation and to improve the translucity of the product so as to receive favorable consumer acceptance.